Local action can reduce global threat

Drug use, improper products contribute to drug resistance
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Dr. Andrew Clark said antimicrobial resistance is a global problem of increasing severity.

"What can we do, and how do we go about doing it?" he asked.

Dr. Clark, who has developed animal health programs in Africa and the Middle East, described research results that indicate bacteria recovered from river sediment downstream from urban areas in India had high antimicrobial resistance, and organisms recovered from chickens in China were resistant to colistin.

Veterinarian-client-patient interaction inside exam room

He was the first speaker in the annual Global Health Summit at AVMA Convention 2018, July 13-17 in Denver. This year focused on antimicrobial resistance and efforts to combat its spread. He described how counterfeit and otherwise inadequate drugs can contribute to selection for drug resistance, as well as the reservoirs of drug resistance in developing countries and the threat they pose to the rest of the world.

Other speakers described actions veterinarians can take to combat antimicrobial resistance, ranging from advocating public policies that support oversight of antimicrobial use to selecting the most appropriate drugs for fighting specific pathogens in their patients. Speakers said the world needs to invest in the development of tools such as vaccines that can reduce the need for antimicrobials.

Dr. Erin Frey, a companion animal veterinarian and member of the AVMA Committee on Antimicrobials, said simple, cheap interventions can help within clinics. She cited study results (JAMA Intern Med 2014;174:425-431) in which physicians prescribed fewer antimicrobials after posting letters in examination rooms that described their commitments to antimicrobial stewardship, appropriate uses of antimicrobials, adverse effects, and the potential for antimicrobial resistance. She said fewer patients expected antimicrobials, and physicians felt less pressure to prescribe them.

Dr. Megin Nichols, activity lead for enteric zoonoses at the Centers for Disease Control and Prevention, said a multidrug-resistant Campylobacter jejuni outbreak in people spread from puppies that had been fed antimicrobials to protect against possible disease.

The outbreak sickened 113 people. Most were connected with puppies at or from Petland stores, and 25 employees of that chain were among the ill, CDC information states.

The outbreak strain was resistant to fluoroquinolones and macrolides, which tend to be the first drugs used. And C jejuni has inherent resistance to other drugs such as penicillin and cephalosporins.

For most of the puppies, she said, veterinarians had prescribed antimicrobials, which could have altered the patients' gastrointestinal flora, creating an environment in which C jejuni could thrive. Beyond immediate illness, C jejuni can cause lifelong effects in humans such as immune-mediated arthritis or Guillain-Barré syndrome.

Outbreak investigators received antimicrobial administration records for 141 puppies. They found about 55 percent had received antimicrobials for prophylaxis only, 38 percent for treatment or prophylaxis, and 1 percent for treatment only. Five percent—seven dogs—had received no antimicrobials, Dr. Nichols said. Most received multiple courses of antimicrobials.

By the number of days administered, metronidazole was the most common antimicrobial used. The drug classes used most often were those shared with human medicine, including sulfas, tetracyclines, macrolides, and quinolones. Testing showed Campylobacter bacteria isolated from the dogs were resistant to eight of nine antimicrobials on the National Antimicrobial Resistance Monitoring System panel, with susceptibility to phenicols.

Dr. Frey said that, in her relief work, she has seen antimicrobial practices differ among veterinarians, even within the same practice. Tracking how often each veterinarian within a clinic prescribes antimicrobials for, say, a respiratory infection could aid conversations.

She described education and other resources available from the AVMA, CDC, American Animal Hospital Association, and universities. And she encouraged veterinarians to find ways to mitigate antimicrobial resistance within their clinics.

Dr. Frey, citing another study (Antimicrob Resist Infect Control 2018;7:46), said veterinarians and pet owners each may think the other wants antimicrobials that are inappropriate for the animal. She said veterinarians need to improve communication with clients.

In a panel discussion among the lecturers, Dr. Frey identified another potential source of antimicrobial resistance: People are able to buy antimicrobials in drug classes shared with human medicine without prescriptions even where they are regulated. In the U.S., for example, people are finding antimicrobials online without prescriptions, including cephalosporins and fluoroquinolones marketed for administration to aquarium fish.

Related JAVMA content:

WHO seeks end to antibiotic use without disease (Jan. 1, 2018)

Survey: Global public confused on antimicrobials (Jan. 1, 2016)